Patents by Inventor S. C. Chen

S. C. Chen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5055199
    Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0.ltoreq. z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x); a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed.
    Type: Grant
    Filed: September 28, 1989
    Date of Patent: October 8, 1991
    Assignee: Aluminum Company of America
    Inventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
  • Patent number: 4867882
    Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z .multidot.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0.ltoreq.z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.3/2x; a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed. The latter method comprises contacting the solution with a sufficient amount of substance consisting essentially of a compound selected from: hydrotalcite, calcined hydrotalcite and mixtures thereof.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: September 19, 1989
    Assignee: Aluminum Company of America
    Inventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
  • Patent number: 4744825
    Abstract: In accordance with the invention, an improved process is provided for the efficient removal and recovery of silver from an impure solution containing silver ions which comprises contacting the silver-containing solution with an activated alumina adsorbent to selectively adsorb the silver ions from the solution and the lower the subsequent effluent discharge to less than 1 ppm silver, treating the activated alumina with a regeneration fluid to recover the silver ions from the adsorbent, and reducing the recovered silver ions to metallic silver.
    Type: Grant
    Filed: December 4, 1986
    Date of Patent: May 17, 1988
    Assignee: Aluminum Company of America
    Inventors: Abraham S. C. Chen, Hubert L. Fleming